Crease-resisting treatment of textile materials



Patented Apr. 15, 1941 CREASE-RESISTING TREATMENT OF TEXTILE MATERIALS,William Watkins, Prestwich, Manchester, England No Drawing. ApplicationJuly 20, 1939, Serial No. 285,625. In Great Britain August 17, 1935Claims.

This invention relates to the finishing of textile fabrics for thepurpose of imparting creaseresistant and crease-recovery propertiesthereto (as for example in the case of fabrics of cotton and artificialsilks, which have little or none of such properties naturally), or forthe purpose of improving the natural crease-resistant andcrease-recovery properties thereof (as for example in the case offabrics of silk and wool) without in either case depriving the materialsof their natural suppleness or softness.

The present application is in part a continuation of my co-pendingapplication Serial No. 110,- 306 filed November 11, 1936, entitledCrease-resistant treatment of textile materials.

Fabrics are considered crease-resistant when they may be crushed orfolded under pressure as by being crumbled in the hand, without having apermanent crease imparted to them, and are considered to havecrease-recovery properties when, after being marked by crushing orcrumpling, they recover from such marking;

In previously known processes for this purpose, there has been an aim tocause the fibres of the fabrics to be impregnated with reinforcingsubstances comprising synthetic resins, and in such manner as to depositthe resin substantially within whilst avoiding its presence between thefibres in substantial amounts. Such known processes have necessitatedthe application of relatively large quantities of the resin-formingbodies; have inhibited the use of fillers in the reinforcing substancesexcept in very small amounts insufficient to impart a filled or loadedeffect to the fabrics; and have entailed the removal (as by soaping-off)of the surplus resins to ensure there being substantially none betweenthe fibres in the finished product. These requirements have rendered theprocess costly and have limited the range of fabrics to which they canbe applied,

The principal object of the present invention is to provide a process orprocesses of finishing textile fabrics, for the purpose set forth, whichis or are entirely free from the drawbacks and limitations of the saidprevious proposals in that (a) much smaller quantities of reinforcingsubstances may be used (although the invention is in no way restrictedto the use of small quantities) and the fine molecular division of theapplied bodies is not a necessity, since it is immaterial whether thereinforcing substances are substantially within the fibres or merelycoat them, or do both; (b) in which fillers or loadings may be used withthe reinforcing substances, if

desired, in amounts sufficient to give filled or loaded effects; and (c)in which there is no necessity for removing any surface deposit orsurfibres) is not detrimental to the process, and does not detract fromthe natural suppleness and softness of the, materials, at least to anyadverse extent.

A furtherobject of the invention is to render the reinforcingsubstances, when of a hygroscopic nature, less or non-hygroscopic, andthus lessen or entirely obviate the tendency of the anti-crease finishto diminish during the passage of time, and also permit the use of awider range of reinforcing substances.

The present invention is based upon the realisation that the essentialrequirement'in a creaseresistant or crease-recovery fabric is that thefibres should be individually reinforced to the correct degree, and thatthey should not adhere together, but should be as free from each otheras in any ordinary untreated fabric, so that relative movement may takeplace between them when the fabrics are subjected to distortion, and sothat the separated reinforced fibres may be free to accommodatethemselves to new relative positions without losing their impartedspringiness and permanent set. Given. such requirement, it appears to bea matter of little or no importance whether the reinforcing substancesare impregnated within, or are substantially between the fibres or arein both such dispositions.

The present invention consists in applying to the fabrics in the form ofa solution or dispersion reinforcement-forming substances of analdehyde-hardenable nature selected from the group consisting of animaland vegetable filmforming substances and synthetic-resin-formingsubstances, in drying the fabrics after the application of suchsubstances, in mechanically working the fabrics to unstick theconstituent fibres from each other, and in heat treating the fabrics inthe presence of an, aldehyde and an accelerator, the heat treatmentbeing such as to harden the reinforcement-forming substance sufficientlyto give the fabrics crease-resistant properties.

Usually the fabrics will be dried after the application of thereinforcement-forming substances, and before the mechanical treatment iscarried'out on the fabric. In some cases however, the mechanicaltreatment may be carried out during the drying and/or hardeningtreatments. Generally, however, the mechanical treatment is done afterthe fabrics are dried and before the reinforcement-forming-substa1ucesare hardened, and in such cases the fabrics require to be kept dry, inorder to prevent the fibres re-- sticking together, as might be the casewhere the unhardened substances are soluble in water. The

term dry in this connection means normally dry, 1. e. the state ofdryness which would subsist in a normal atmosphere.

By the term reinforcement-forming sub- 'to impart to the fabrics a morevigorous individual fibres, and which can then be hardened by chemicaltreatment to a degree sufiicient a springiness or temper, the effect ofwhich on the fabric be described as an anti-crease effect, according tothe standards now adopted. Those dispersions or other forms of substancewhich on evaporation leave a granular or non-continuous depositincapable of imparting the required springiness or temper, are notintended to be included in the term reinforcement-forming substances.

The solutions or dispersions of the reinforcement-forming substances arefrequently of a viscous consistency, more of a paste than a liquid,

"but as entry or the substances within the fibres the success of theinvention,

is not essential to this is no disadvantage.

The term "aldehyde-hardenable reinforcement-forming-substance means asubstance as defined in the last preceding paragraphs and which may behardened by heat-treatment'in the presence of formaldehyde,paraform-aldehyde or an analogous or homologous aldehyde.

The reinforcement-forming substances will be of an adhesive orfilm-forming nature and may include such widely diverse substances ascasein, albumen, starches, modified starches, dextrine,

. animal glues and gelatines, vegetable gelatines (such as thoseobtained from sea-weed), locustbean gum, gum arabic and like gums,algin, and metallic salts of alginic acid, and some of the syntheticresin-forming substances, all of which have the property of beinghardened by heattreatment in the presence of an aldehyde, to formreinforcements to the extent required for an anti-crease effect. Some'oithe reinforcementforming substances named are more efiective thanothers.

V In this specification, the term mechanical treatment is intended toinclude any mechanical or manual treatment which will separate (unstlckor prevent sticking together of) the individual fibres to which thereinforcement-forming sub stances have been applied, and does notinclude such processes as boiling or soaping off or other chemicaltreatment. The fabrics will in .most cases require to be treated both ina warpwise and weftwise direction at least. One method of mechanicaltreatment contemplated by this invention, and applicable to thetreatment of fabrics according to all the following examples is thepassing of the fabric under and over breaker bars and through a cold nipon a mangle several times, the treatment being carried out to asufficient degree of intensity and a sufficient number of times toseparate the individual fibres, A

.stentering process, or the use of cxpanders may be included to give aweftwise treatment, especially if the fabrics havebeen dried narrow. Fortreating small articles, a manual treatment by crumpling and scrubbingtogether severely would have the desired result. Some of the substancesnamed hereinrequire a more intensive mechanical treatment than others,the degree of treatment depending upon the adhesive power of the appliedsubstances. For instance, starch requires treatment than does albumen.

It is to be understood that not only are the threads of a fabric to beunstuck from each other, but also the component fibres of the threadsare to be unstuck, from each. other. The word unstuck is used merely toqualify the term sepis entitled to,

aration, in that it is not to be a separation by complete removal of thefibres out of contact with each other, as bytearing apart, but is to bemerely an avoidance of or elimination of adhesion together. The basis ofthe invention is that the fibres, having had their springiness increasedby the hardened'applied substances, are to be free to move relatively toeach other; and a mechanical treatment during drying or hardening whichwould prevent sticking of the fibres together would serve the purposealso. The primary object of the mechanical treatment is to unstick thefibres and thus make their relative movement possible. It is a colateralresult of the mechanical treatment that the fabrics are rendered lessharsh or stiff, and although such colateral result is useful, and isdesired, the anticrease effects depend fundamentally on the mechanicaltreatment being sufficiently intensive to bring about the separation(loosening) of the fibres, and on the fibres having the required degreeof springiness.

The term hardening connotes a reaction which increases the hardness ofthe applied reinforcement-forming substances to such a degree that thetreated fibres are rendered sufficiently springy to impart ananti-crease effect to the fabric. It has been found that the degree ofhardening required is such that if applied to the reinforcement-formingsubstances alone, i. e., when not on or in textile fibres, it will makethe resultant substance hard and brittle, i. e. glasslike. When the.reinforcement-forming substances are hardened to this extent, on or inthe fibres of a fabric, the natural plasticity ofthe fibres modifies thebrittleness of the reinforce- I ment, and the hardening process thenresults, in

springy, tempered, fibres, which collectively give to the fabric aresistance to creasing.- Any less degree of hardening which would merelyleave the resultant substance flexible if treated alone (i. e., when noton or in textile fibres) or which would be overcome by the naturalplasticity of the fibres it carried out thereon or therein, is

found not to be sufficient and is not contemplated able that somereinforcement-forming substances (as for instance some syntheticresin-forming bodies) will be self-hardening over a period of time, andthe term hardening'is intended to include such ageing processes. Inthose cases,-

also, if, the fibres, have been separated, care will be taken to preventany re-sticking of them by dissolving of the reinforcement-formingsubstances during the ageing period. Further, in some cases thehardening process will be carried out under pressure, if the requireddegree of hardness is not obtainable otherwise; This will be especiallyso with the natural substances such as casein, starch etc., where theanti-hygroscopic bodies referred to below are not added to thereinforcement.

During the hardening process, it is necessary that there be anaccelerator present with the reinforcement-forming-substance and thealdehyde, and also that there be an excess of the aldehyde, that is tosay, a greater quantity of aldehyde than is theoretically necessary toharden the reinforcement. It is believed that, with an excess ofaldehyde present, not only does the aldehyde react with thereinforcementforming substance, but also with the fabric itself, andthat such collateral reaction is useful in giving permanence to theanti-crease effect.

The aldehyde which is to take part in the hardening process, may beapplied to the fabric,

in various ways. Most conveniently it is added to the solution ordispersion of the reinforcementforming-substance, with which the fabricis to be impregnated, and applied to the fabrics in that solution ordispersion. When however the reinforcement-forming-substance is such aswould react with or be precipitated by the aldehyde if added to thesolution or dispersion, that substance (in solution or dispersion) willbe applied to the fabric first, and the fabric, with or without anintermediate drying and mechanical working,

then passed into a solution or dispersion of the aldehyde andaccelerator, and whatever other substances are to be present during theheat treatment. Alternatively, the fabric may be passed through analdehyde both first of all before having the reinforcement-formingsubstance applied to it, and in such event as well as when thereinforcement-forming substance and the aldehyde are appliedsimultaneously, the fabric may be allowed to steep in the bath forseveral hours, as this improves the result obtained.

Other methods of applying the aldehyde (for example paraformaldehyde) tothe fabric are:

(a) Paraformaildehyde powder may be placed in the enclosed chamber inwhich the hardening is to be effected, the powder volatilising under theinfluence of heat and thereby obtaining contact with the treatedfabrics; (b) The paraformaldehyde powder may be dusted on to the fabricsin known manner, say prior to their being placed in the pressurechamber, and the heat and pressure applied as in the previous case: (c)The paraformaldehyde may be dispersed in a viscous, inert, non-alkalinesolution and padded on ma back-cloth, the back-cloth then being dried ata low temperature (say 40-50 C.) to prevent premature volatilisation andthe treated fabric and back-cloth be rolled up together in batch formand placed in the heating chamber, the

paraformaldehyde being driven off as the temperature is raised, andhardening the reinforcing substances in the treated fabric. In thislastmentioned instance, there is not the same need for an increase ofpressure in the chamber, since the aldehyde vapours are more or lessimprisoned due to the rolling-up of the fabrics, and generate asufficient pressure by their vapourisation. (d) The fabric is sprayedwith formalin solution. Generally the amount applied and/or theconcentration of the solution is such that there is sufficientformaldehyde to effect the hardening, but not sufficient water to causethe fibres of the treated fabrics to stick together. After having beensprayed, the fabric is allowed to sand a little while to allow thesolution to distribute itself evenly in the fabric, and the fabric isthen placed in the heating chamber as usual: (e) Where the paddingsolution or paste containing the reinforcement-forming substances issufilciently viscous to hold the paraformaldehyde in suspension, theparaformaldehyde may be dispersed in such padding solution or paste. Inthis case, the drying of the padded material will be carried outcarefully so as not to vapourlse the paraiormaldehyde prematurely. Inthis method of application, no free alkali is allowed to be present asit would cause the paraformaldehyde to go into solution, with apparentalteration of its properties, since it wouldnot then do its hardeningwork so effectively.

Accelerators suitable for use in the hardening reaction are acid saltssuch as potassium tetroxalate, sodium bisulphate and alumina sulphate;acid-liberating salts such as ammonium salts of organic and of inorganicacids (e. g. ammoniuml oxalate, ammonium chloride and ammoniumphosphate); and some weak acids, such as tartaric, acetic, and oxalicacid. Other accelerators which may be employed are ammonium dihydrogenphosphate; and small amounts of urea mixed with ammonium chloride orwith alumina sulphate or with formic acid.

During the hardening process, the presence of moisture will be carefullycontrolled so that whilst there will be sufficient moisture present (ifnecessary) to enable the reaction to proceed, there will be insufficientto cause the fibres to restick together. In some cases it may benecessary to condition the fabric, as by ageing, after drying and beforeheat-treating it. If by accident (or otherwise) there should be aresticking of the fibres, due to some of the reinforcementformingsubstances going into solution, a further mechanical treatment may beadopted, before or after the hardening treatment, to undo any suchresticking. The separation of the fibres is of course more dimcult toeffect after the hardening treatment than before, and in some casesmight be impracticable.

The hardening treatment with paraformalldehyde or the like is carriedout at an elevated temperature, either at atmospheric pressure, as forinstance in an open oven, or at a superatmospheric pressure in a closedchamber. A mechanical pressure would not be used, as that would tend tostick the fibres together again. When synthetic resins are to be thereinforcing-substances the whole of the reaction between theresin-forming materials, may be completed in one stage.

When synthetic resins are used as the reinforcing-substances, theimproved process presents at least three outstanding advantages over theprior proposals referred to above, in which the resins had to besubstantially within and not between the fibres. Firstly, the quantityof resins necessary is much less than is required in the prior art;secondly, it is not necessary to condense the resins to an intermediatestage before their application to the textile materials; and thirdly,loading or filling materials may be added to the resins in quantitiessufficient to give loaded or filled effects without detriment to theanti-crease result. Examples of loadings or fillers which may be addedwith the synthetic resins are French chalk, alumina salts, gumsubstances, starches,

and dextrines, with or without a thickener when desired to assist theirdispersion. The use of certain of the gum substances is especiallybeneficial as they overcome or counteract any harshness or dryness offeel which may otherwise be imparted to the fabric by the resins. It isa Wellknown fact that, weight for weight, a tube of material is, withincertain limits. more resistant to bending than-is a rod. Since, by thisinvention, the reinforcing substances may be coated on the fibres in theform of a sheath or tube, as would be the case with such substances asstarches, which do not readily penetrate the fibres. the presentinvention gives a more eflicieiit and, in consequence, lose theirreinforcing properties too rapidly, have their hygroscopy removed orcounter-acted by the admixture with them or the formation among them ofsuitable nonhygroscopic bodies, such as those of the synthetic resinswhich do not interfere with the hardening process. This step is notalways required; for instance, when voiles or like fabrics dyed withaniline black are being treated, the very inert,

aniline pigment may itself be sufficient to counter-act the hygroscopicnature of the reinforcing substances.

Usually, those of the reinforcement-forming substances which are naturalproducts, as distinct from the syntheticproducts will be hygroscopicevenafter hardening and will therefore require to have the anti-hygroscopicsubstances added to them (unless these are already present in suflicientamounts in the fabrics) when more permanent results are. desired.

In carrying out this feature of the invention, since the condensation orpolymerization of the synthetic resins (when used) to counteracthygroscopy may be effected by a process which will also harden thereinforcement-forming, substances, namely by heat-treatment with anaidehyde, the resin-forming bodies may be mixed with thereinforcement-forming substances, the

two applied to the textile fabrics in one operation, and the tworeactions then carried out simultaneously. The proportions of synthetictresins necessary in this part of the process, merely for theiranti-hygroscopic properties, are, even in the largest amounts,insufficient of themselves to impart satisfactory crease-resistingeffects to the fabrics.

In useful examples of the carrying out of the invention, where thereinforcing substance is other than casein, such substance is dissolvedor dispersed in water to a concentration of say avoiding the presence ofalkalies, and a quantity of an aldehydesubstance, such as formaldehyde,is added to the solution or dispersion. The fabric is first impregnatedwith the solution or dis- 'persion and afterwardsnipped off on a "manglesolution or dispersion. The fabric is next dried thoroughly, at about110 C., and is then broken down, for example by being passed over andunder knife-edged bars and through a cold nip on a mangle (Whilst stilldry) to a degree. sumcient to separate the fibres, and is then heattreated, wither without pressure at a temperature of about 130 C. for aperiod long enough to convert the applied reinforcing substances into ahard, non-plastic, non-adhesive, insoluble condition which gives to thefabric crease-resistant and crease-recovering properties. When it is desired that the reinforcement-forming substances give greater weight tothe fabrics, the concentra tion of the solution or dispersion may beincreased considerably.

When casein is to be employed as the reinforcing substance, variationsin the above procedure are required. The fabric is first impregnatedwith EXAMPLE1.Reinforcement formed from casein The fabric is firstimpregnated with a 3% to 5% aqueous solution of casein, the caseinhaving been brought into solution with the aid of ammonia, and is thendried and afterwards broken down to separate the fibres from each other.When thoroughly broken down, the fabric is impregnated with thefollowing:

Urea in the form of 4 ccs. of a com- 0.6 Thio-urea mercial resin syrupgrams 0.6 Potassium tetroxalate do 0.4

Formalin (commercial 40%) cubic centimeters 30 The total being made to100 ccs. with water.

The fabric was allowed to remain in this mixture for two hours, at theend of which time it was removed from the bath, nipped off in a mangle,and dried thoroughly at C., and then subjected to a second breaking downtreatment to separate the fibres from each other again. After beingconditioned to an 8% moisture content (or thereabouts) the fabric washeated for 30 minutes at a temperature of 130 C. The heat-treatment maybe carried out at atmospheric or superatmospheric pressure as desired.

The ultimate product was found to havemarkedly increased resistance tocreasing, and to meet the generally-adopted commercial standards ofcrease-resistance.

The resin formed from the syrup acts as a protector for the casein, topresent hygroscopy in the finished article, the quantity of resin usedbeing much too little to be of itself a reinforcement for the fibres ofthe fabric. Other protectors which maybe used with casein for a likepurpose are, resorcin and lime, phthalic acid resins, and likesubstances which will harden to the required degree.

EXAMPLE 2.Reinforce1rtent formed from. casein The fabric was treated asin Example 1, except that the aldehyde-containing impregnating bath wasmade up asfollovvs:

Tartarlc acid grams 2 Alumina sulphate do 0.5 Urea do 1 Formalin(commercial 40%) cubic centimeters 20 Made up to ccs. with water.

ExAMrLE 3.--Reinforcement formed from albumen The fabric was impregnatedin the following: Blood albumen grams 5 Tartaric acid do 1 Aluminasulphate -do 1 Formalin (commercial 40%) cubic centimeters 20 Buiked to100 ccs. with water.

After remaining in th bath for two hours the fabrics were removed, driedthoroughly at 90.C., broken down to separate the fibres, conditioned to8% moisture content, and heated for 30 minutes at 130 C. either atatmospheric or super-atmospheric pressure, as desired.

EXAMPLE 4.Reinforcement formed from albumen The fabric was impregnatedin the following for two hours, and the process then continued as inExample 3.

Blood albumen grams Tartaric acid do 2 Alumina sulphate do 1 Urea 1Formalin (commercial 40%) cubic centimeters..- 20 Bulked to 100 ccs.with water.

ExmLs 5.--Rein/orcement formed from albumen The fabric was impregnatedin the following for two hours, and the process then continued asTartaric acid grams 2 Bulked to 100 ccs. with water. 1

EXAMPLE 6.Reinforcement formed of resin The fabric was impregnated inthe followin for two hours, and the process then continued as in Example3, except that the drying was carried out at 110 C:

Commercial resin syrup (contained 3.32 grs. urea resin and 3.32 grs.thio-urea resin) cubic centimeters-.. 12

Formalin (40%) -do Tartaric acid ram-.. 1

Bulked to 100 ccs. with water The above examples may be modified, inthat instead of the fabric being steeped in the solution astraightforward impregnation or padding-on may be carried out.

EXAMPLE 7.--Reinfcrcement formed of resin The following mixture waspadded on to the fabric and the fabric then dried at 110 C., and theprocess then continued as in Example 3.

Resin syrup (commercial) cubic centimeters' Formalin (40%) do 10-Tartaric acid grarn 1 Bulked to 100.ccs. with water.

Examms 8.-Reinforcement formed of a filled resin To 10 cos. ofcommercial resin syrup, containing 6 grms. total resin was added:

Formalin cubic centimeters 20 Locust-bean gum paste -grams French chalkdo 10 Potassium tetroxalate do 0.6 Water -cubic centimeters" 19.4

Total do 100 onwhite materials. It could, however, be tinted for use oncoloured goods.

Exmtn 9.Rein,forcement formed from a metallic salt of aluinic acid To 75cos. of 5% alg inate of alumina solution was added:

Formalin (40%) -cubic centimeters-.. 25 Water solution of a commercialresinsyrup containing 0.66 grm. urea and 0.66 grm. thio urea, alreadyconverted to an intermediate stage of concentration ccs- Bulked to ccs.with water.

The fabric was impregnated in the mixture and the process then continuedas in Example 8.

Exsuru: 10.Reinjorcement formed from starch To 4 grms. of starch made toa paste in the usual way was added:

Commercial resin syrupmcubic centimeters 6 Tartaric acid "grams" .5Alumina sulphate do .5 Formalin 40% cubic centimeters 3 Bulked to 100cos. with water.

The fabric was impregnated with the mixture and the process continued asin Example 8.

Other gums or fillers can be used, and also where a waterproof effect isdesired at the same time this can be obtained by the addition of acetateof alumina.

The processes constituting this invention may be applied to textilefabrics which have passed through the usual so-called finishingprocesses (dyeing, lustring, mercerlsing, etc.) or to unfinished orsemi-finished materials, and in some cases may be incorporated with theusual finishlng processes.

It is to be understood that the invention is not restricted to theindividual substances, quantities, temperatures and pressures herein setforth, nor are the time periods mentioned the only periods practicable.

What I claim is: i

1. The process of imparting crease-resistant properties to textilematerial, which includes loading the fibres of the material with anencasing of aldehyde-hardenable organic reinforcement-forming substance,drying the, material after the application of the aldehyde-hardenablesubstance to form a coating around the constituent fibers, thensubjecting the material while still dry to mechanical treatment withoutbreaking the coating of the fibres to render the fibres in a state ofnon-adhesion to each other, incorporating an aldehyde capable ofreacting with the aldehyde-hardenable reinforcement-forming substance toharden the same, and hardening the reinforcing substance by heat undersuperatmospheric pressure to a degree sufficient to give the materialcrease-resistant properties.

2. A process according to claim 4 in which the aldehyde-hardenablesubstance is starch.

3. A process according to claim 4, wherein the aldehyde-hardenablesubstance is a synthetic urea formaldehyde type resin-forming substance.

4. A process for imparting crease-resistant properties to textile fabricwhich includes applying to the fabric a liquid medium containing an.aldehyde-hardenable film-forming organic reinforcement substance, dryingthe fabric to deposit such substance as a coating around the constituentfibers, mechanically working the fabric to unstick the constituentfibers from each constituent fibers, mechanically working the fabric tounstick the constituent fibers from each other without breaking thereinforcement coating carried by the individualfibers, and heat treatingthe fabric under super-atmospheric pressure in contact with an aldehydeand an accelerator, the heat treatment being such as to harden thereinforcement-forming substances sufflciently to give the fabriccrease-resistant properties.

6. A process according to claim.4 in which there is included with thefilm-forming substance, added aldehyde-hardenable non-hygroscopic bodiesin an amount suflicient to counteract hygroscopy in the reinforcement.

7. A process according to claim 4 in which there is included with thefilm-forming substance prior to its application to the fabric, syntheticurea formaldehyde type resin forming materials and forming the resinduring and by the heat treatment which forms the reinforcement.

8. A process according to claim 4 in which the hardenable substance isan albuminous substance.

9. A process according to claim 4 in which the hardenable substance isan albuminous sub!- stance, and in which there is included with saidalbuminous substance, synthetic urea formaldehyde type resin formingmaterials and forming the resin during and by the heat treatment whichforms the reinforcement.

10. A process for rendering textile fabric crease-resistant, whichincludes first padding onto the fabric to an expression of from to a 5%dispersion in water of an albuminous substance, next in drying thefabric at about C. to form a coating around the constituent fibers, thenin conditioning the fabric to about 8% moisture content, next inmechanically treating the fabric by passing it several times through abreaking machine and through a cold m'p on a. mangle to unstick thefibers, and finally in heat-treating the fabric in contact with analdehyde at a temperature of about C., for 30 minutes.

WM. WATKINS.

